Die for pressing sound-records.



I T. STEVENTON. DIE FOR PRESSING SOUND RECORDS.

' APPUCATION HLED MAY 4. 1915. 1,2? 5, 1 00. Patented Aug. 6, 1918.

3 SHEETSSHEET lavwmatoi T. STEVENTON.

. DIE FOR PRESSJNG SOUND R DS.

' APPLICATIOM FILED MAY 4, 4 1 ,275,109, Patented Aug. 6, 1918. 3 SHEETS-SHEET 2.

1% TIWWWW/H c.3- M W 1 r r P I 6 T. STEVENTON.

DIE FOR PRESSING SOUND RECORDS.

APPLICATION FILED MAY 4. 1915.

Patented Aug. 6, 1918.

3 SHEETSSHEET 3.

MI 6 3 55 i THOMAS STEVENTON, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO AMERICAN GRAPH- OPHONE COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF WEST VIRGINIA.

DIE FOR PRESSING SOUND-RECORDS.

Specification of Letters Patent.

Patented Aug. 6, 1918.

Application filed May 4, 1915. Serial No. 25,815.

This invention relates to dies for pressing sound-records bythe use of the usual or any suitable matrix commonly employed in the art for this purpose. The object of the invention is to provide means whereby the thermoplastic material in which the record is to be pressed may be subjected to the requisite pressure and under the proper conditions to secure a perfect impression'from the matrix, or matrices when a plurality are used, and at the same time enable the dies to be easily and rapidly handled by the operator.

In the prior practice of the art, it has been common 'to provide a pair of matrixcarrying dies containing an annular groove surrounding the matrices when the dies are in position with relation to each other, said dies having a thin annular wall interposed between the matrices and said annular groove. This groove atl'ords space into which excess material in the record tablet may escape during the process of'pressing the record, and the annular wall referred [0 serves to cut off or stop any further escape of the record material when the pressure on the material reaches its maximum. thereby cnablin such pressure to be maintained undiminis ed during the cooling of the record. In such dies, however, the press-rare on the material constituting the record tablet cannot be increased after theinstant when the cut-off walls serve to close the escape for the excess record material.

One of the objects of the present invention is to provide means whereby the pressure upon the matrices, and therefore upon the record material between the matrices, may be increased after all escape of excess material ceases, to the end that the thermoplastic record material may be forced into more intimate relation with the matrices, and thereby a more perfect record secured. "With this object'in view, the invention consists in constructing the die in two parts, one 0f which is provided with the usual or any suitable cut-oft walls to close the escape of the material from beneath the matrix,

and the other of which transmits the pres- 1 sure directly to the matrix, the two parts being arranged so as to move together under the pressure until the cutting-01f action is complete, after which the part transmitting the pressure to the matrix is capable of a further movement whereby the plastic material is subjected to increased pressure after all escape of the thermosplastic material has been cut off, thereby forcing said thermoplastic material intojvery intimate contact with every portion of the matrix. Preferably, this relative movement between the two parts takes placeagainst the action of a yielding tension resulting from the use of a suitable metal spring or yielding cushion reacting between the parts. The yielding means referred to serve not only to readily permit the dies to be brought fully home with relation to each other, but also serve, when pressure is relieved, to start the separating action, to the end that the workmen may quickly and readily separate the dies and remove the record. Other features of the invention will appear in the appended description, and will be pointed out in the claims.

The inventive idea involved is capable of receiving a variety of mechanical expressions, two of which, for the sake of illustrating the invention, are shown in the accompanying drawings, but it is to be expressly understood that such drawings are for the purpose of illustration only, and not for the purpose of defining the limits of the.

invention, reference being had to the appended claims for this purpose.

In said drawings- Figure 1 is a plan view of the invention;

Fig. 2 is a cross-section on the line 2-2 of Fig. 1, looking in the direction of the arrows, and also showing in outline the heads of a hydraulic press with which the dies may be employed;

Fig. 3 is a sectional detail on the line 33 of Fig. 1;

Fig. 4 is a detail illustrating the construction of one of the several springs employed;

Fi 5 is a sectional view of such spring in position, and on the line of Fig. 1;-

is a plan view of another expression showing a rubber of Figs.

Fig. 6 of the same inventive idea, cushion substituted for the springs 1 to 5; and

Fig. 7 is a detail sectional view taken on the line 77 of Fig. 6.

Referrin to Figs. 1 to 5 of the drawings, in which Ike reference numerals indicate like parts throughout the several views, 1 IS the upper and stationary head of a hydraulie press, and 2 is the lower and movable head of such press. It is between the two heads 1 and 2 that after described,. are placed in compressing the record. The lower die 3 consists of a plate of metal, here shown as substantially rectangular inform, and rovided with a central depression in whic is placed the matrix 4. Surroundmg the matrix-receiving depression in the die 3 1s an annular groove 5, separated from the matrix-receiving depression in the die by a narrow wall 6. Immediately in the center of the die is a pin 7, whose tapering upper portion projects above the surface of the dle.

The upper die consists of a plate 8 having a circular opening of approximately the diameter of the matrix to be employed, within which opening is mounted a round compression plate 9 having a rabbeted shoulder 10 formed thereon (Fig. 3), which 18 engaged by a corresponding shoulder 11 on the ring 8, the internal diameter of the shoulder 11 being less than the external diameter of the shoulder 10, to the end that the ring 8 rests upon the shoulder of the plate 9 when the parts are in position. Preferably, an annular groove 12 is formed in the under side of the ring 8, with a narrow wall 13 betweensaid groove and the interior wall of the die, though it is not essential that there be a groove 5 and a groove 12. since one or the other of these grooves may be omitted if desired. The upper face higher than the top of the plate 8, so that when the plate 9 is in position in the plate 8, there is formed a suitable depression or space for receiving the upper matrix 14. A plurality of pins 15, here shown as three in number, are mounted so as to project up- Ward from the die 3, and enter corresponding holes or openings in the ring 8. for the purpose of properly positioning the parts with relation to each other. The plate 9 is provided with a central opening 16. and a hollow cap 17 is located in said opening, and extends down over the conical upper portion of the centering pin 7 which cap 17 forms the means for molding the requisite central opening in the record.

For the purpose of permitting increased pressure to be exerted upon the matrices after the escape of the record material into the annular space surrounding the matrices has been closed by the cut-off walls 6, 13,

the die plates, hereinthe act of of plate 9 rises.

emme yielding means are provided which will allow the plate 9 to continue to move downward and press the matrix 14 dowmvard after the exit of the I'QPOIti material is closed by the meeting of the walls (3 and 13. Any suitable yielding means may be. employed for this purpose. As shown in Figs. 1 to 5, the plate 9 is provided with a series of radially extending spring blades 18, which are dove-tailed into suitable grooves in the upper surface of the plate and secured by screws 19, as will be readily understood by an inspection of Fig. 5. The inner ends of the spring blades should be flush with or below the upper surface of the plate 9. As here shown they are flush with the upper surface'of the plate. The ends of the spring blades 18, which project. outward beyond the periphery of the plate 9. are bent downwardly, and suitable radial grooves 20 are formed in the plate 8 for the reception of the spring blades, as will be readily under Stood from an inspection of Figs. 1 and When the parts are in position. and in the absence of pressure, the springs 18 act to hold the plate 9, with its shoulder 10.snugl v up against the shoulder 11 on the plate and the upper surface of the plate 9 then projects slightly above the surface of the plate 8, as will be clearly understood from an inspection of Fig. 3. But when the cutoff walls 6-13 meet, the spring blades 18 yield and permit the plate 9 to be still further depressed, and thereby bring increased pressure to bear on the now wholly confined record material.

Operation: When a record is to be pressed. the matrix 1 is placed in the die 3, and the matrix 11 is placed in the die composed of the plate8and the plate 9, the centering pin 7 passing through the central opening in the matrix 1. A blank tablet is then placed in position with its central opening over the cap 17, and the upper die with its contained matrix is inverted over the cap, the pins 15 serving to properly position the two dies with relation to each other. With the parts in this position, the upper surface of the plate 9 will project slightly above the surface of the plate 8, and the annular groove 5 in the lower die will coincide or register with the annular groove 12 in the upper die.

leaving an annular space surrounding the dies, and the adjacent faces of the partition walls 6 and 13 on the two dies will be slightly separated so as to leave communication between the groove and the interior of the dies. The parts being heated in a man ner well understood in the art. and pressure being applied. the excess thermoplastic (heated) material constituting the record tablet will be forced radially outward h, tween the partition walls 6 and 13 into the annular groove 5-12 until the faces of the lower die and the plate 8 are brought tightly lit) together, thus closing off the escape of the material into the groove 512. The plate9 continues to move downward under the pressure, and thus forces the matrices into intimate contact with the recordmaterial which is wholly confined, all escapebeing cut off by the walls 6 and 13. The pressure is maintained until the parts have been allowed to cool sufficiently to permit the removal of the molded record. Upon the pressure being relieved, the springs 18 act to slightly lift the plate 9, which facilitates the separation of the matrices from the pressed record.

Referring now to-the form of the invention illustrated in Figs. 6 and 7, each of the die plates 21 and 22 is formed with a central circular opening, and projecting inward from the wall of the opening in the plate 21 is an upwardly facing flange 23 and a like flange 24, but downwardly facing, pro ects inwardly from the peripheral wall of the opening in the plate 22; The usual annular escape groove is formed in one or both of said flanges, and the usual or any suitable cut-ofl? walls 25 are formed on the inner part of the adjacent surfaces of said flanges. A circular plate 26 fits into the circular opening of the plate 21, said plate 26 being provided with a downwardly facing peripheral flange 27 projecting radially outward over the flange 23 on the plate 21. A resilient member, such as a vertically corrugated spring-ring or a cushion or gasket 28 of resilient material, such as rubber, is interposed between the adjacent faces of the flanges 23 and 27 and the two plates 21 and 26 are preferably secured together by means of a series of screws 29 passing through the flange 23 and into the flange 27, but leaving the two plates free to have relative vertical movement with relation to each other.

When the plates 21 and 26 are thus assembled, the upper surface of the plate 26,

which constitutes the follower plate over the upper matrix 30, occupies a slightly higher level than the upper surface of the frame plate 21.

The construction of the lower die is simi lar to that of the upper die, except that the parts are-inverted, there being a follower plate 31 with flange 32 engaging the flange 24. and having the rubber cushion 33 interposed between the flanges, and the screws 34 engaging the parts. When the parts are assembled, the plate 31 projects slightly lower than the plate 22 when the cut-off walls on the respective flanges meet, to the end that the follower plate 31 may continue to move to force the matrix 35 upward after the Walls 25, 25, have acted to cut off the escape of surplus material.

The resilient member may be of any suitable form that permits of compression and return, and that has room for the material to get out of the way of the mutually-approaching plates; and, preferably, may be in the form of a ring having radially projecting saw-teeth 36, as shown in Fig. 6, to the end that space may be provided between the teeth for the expansion of the elastic ma terial when pressure is brought thereon to finally close-the dies.

The construction shown in Figs. 6 and 7 has the advantage of being capable of use in a smaller press than that shown in Figs. 1 to 5, since thespace occupied by the radially projecting springs is eliminated. Butthe fundamental principle of operation is the same, as will be readily understood by comparing the two constructions.

By the use of the dies as described, means are provided for the ready escape of any excessmaterial from the dies, after which all escape is cut off and the maximum pressure where but a single die and matrix are employed. In that case, the only change might consist of using a single matrix and a single smooth-faced plate (instead of two matrices), or, there might be but a single frame plate and a single follower plate, combined with means for permitting the follower plate to have independent vertical movement with relation to the frame plate after the escape of the excess material has been stopped by the cut-off walls, thus subjectingthe ma; terial. of the record, when completely confined, to a greater pressure than that to which it was subjected prior to and up to the moment of action'of the cut-off walls.

What is claimed is 1. In a device for pressing sound-records, a sound record matrix, means for applying pressure to thermo-plastic record-material in working relation with said matrix, means for cutting off the escape of record-material from working relation with said matrix, and means enabling an increase of pressure on said record-material after said secondnamed means has operated.

2. In a device for pressing sound-records, a sound record matrix, means for applying pressure to thermo-plastic record-material in working relation with said matrix, means for cutting off the escape of record-n'iaterial from working relation with said matrix, and means whereby said second-named means and said matrix may have relative movea in working relatlon ment that the pressure on said recordmaterial may be increased after said secondnamed means has operated.

3. In a device for pressing sound-records, a sound record matrix, means for applying pressure to thermo-plastic record-material in working relation with said matrix, means first permitting and then cutting ed the escape of record-material from working relation with said matrix, and means whereby said second-named means and said matrix may have relative movement that the pressure on said record-material may be increased after said second-named means has operated to cut ofi' the escape of recordmaterial.

4. In a device for pressing sound-records, a sound record matrix, means for applying pressure to thermo-plastic record:materia1 inworking relation with said matrix, means for cutting off the escape of record-material from working relation with said matrix, and resilient means providing for relative movement of said second-named means and said matrix whereby the pressure on said record-material may be increased after said second-named means has operated.

5. In a device for pressing sound-records, a sound record matrix, means for applying pressure to thermo-plastic record-material in working relation with said matrix, and means for cutting off the escape of recordmaterial from working relation with said matrix, said second-named means and matrix being relatively movable whereby after said second-named means has operated the pressure on said record-material may be increased.

6. In a device for pressing sound-records, a sound record matrix, means for applying pressure to thermo-plastic record-material in working relation with said matrix, and means first permitting and then cuttingoif the escape of record-material from working relation with said matrix, said secondnamed means and matrix being relatively movable whereby after said second-named means has operated to cut off theescape of record-material the pressure on said recordmaterial may be increased.

7. In a device for pressing sound-records, a sound record matrix, means for applying pressure to thermo-plastic record-material with said matrix, and relatively movable means for cutting off the escape of record-material from working relation with said 'matrix, said last-named means after cutting off the escape'of recordmaterial having movement relatively to said first named means to enable an increase of pressure by said first-named means on said record-material.

8. In a device for pressing sound-records, a sound record matrix, means for applying pressure to thermo-plastic record-material in working relation with said matrix, rela-f tively movable means for cutting 0d the escape of record-material from working relation with said matrix, said last-named means after cutting off the escape of recordmaterial having movement relatively to said first named means to enable an increase of pressure by said first-named means on said record-material, and resilient means opposing such movement. 1 1

-9. In a device for pressing sound-records, the oombbination of a sound record matrix, a two-part die whose parts are capable of relative movement, yielding means reacting between the parts of said die, and means for cutting off the escape of excess record-material before the completion of said relative movement.

10. In a device for pressing sound-records, the combination of a sound record matrix, a die comprising a plate having an opening therethrough and a second plate in said opening, said plates being provided with oppositely disposed shoulders, yielding means reacting between said plates, and means on one of said plates for cutting off the escape of record-material during the pressing operation.

11. In a device for pressing sound-records, the combination of a matrix-bearing die comprising a plate having an opening with an overhanging annular shoulder and a second plate fitting in said opening and having an upwardly facing peripheral shoulder extending under said overhanging shoulder, springs reacting between said plates and tending to hold said shoulders in contact, a second .matrix-bearing die, and means for centering said dies with relation to each other.

12. In a device for pressing sound-records, the combination of a matrix-bearing die, with a second matrix-bearing die comprising a plate with a central opening and a second plate fitting in said opening and capable of movement therein, one of said plates having an overhanging surface engaging a corresponding surface on the other plate, springs tending to hold said surfaces in engagement, and means for centering said matrix-bearing dies with relation to each other.

13. A matrix-bearing die comprising a plate with an opening therein, a second plate fitting in said opening and having a shouldered surface engaging a corresponding shouldered surface on the first plate, and springs reacting between said plates and tending to hold said shouldered surfaces in engagement.

14;. A matrix-bearing die comprising a plate with an opening therein, a second plate fitting in said opening and having a shouldered surface engaging a corresponding surface on the first plate, and a plurality of radially extending springs secured to said second plate and reacting against said first plate, and tending to hold. said shouldered surfaces in engagement.

15. The method of pressing sound-records which consists in heating thermo-plastic sound record-material, placing the heated material in Working relation with a sound record matrix, cutting off the escape of the plastic material, and subjecting the confined material to pressure.

16. The method of pressing sound-records which consists in heating thermo-plastic record-material, subjecting it to pressure in contact with a sound record matrix, cutting ofl' the escape of the plastic material, and subjecting the confined material to further pressure.

17. The method of pressing sound-records which consists in heating thermo-plastic sound record-material, subjecting it to pressure in contact with a sound record matrix and expelling surplus material, cutting ofi? the escape of the plastic material, and subjecting the confined material to increased pressure.

18. The method of pressing sound-records which consists in heating thermoplastic sound record material, subjecting a mass of said heated material in excess of the amount required to make a record to pressure when in contact with a sound record matrix, permitting the escape of the excess material during the first stage of the pressing operation, and then cutting off the escape of said excess and increasing the pressure on the remaining mass.

In testimony whereof I specification in the ing witnesses.

have signed this presence of two subscr1b- THOMAS STEVENTON.

Witnesses:

' LESLIE S. EASTMAN,

JOHN S. GRIFFITH. 

